The present invention relates generally to display interfaces for signal generators and more particularly to a signal generator display interface having parameter edit screen layers having improved parameter edit screen displays of text, waveforms and channels for selecting desired combinations of parameters for the generation of output signals.
Signal generators are used for providing electrical signals having user defined characteristics to electronic circuits under test to verify the performance of the circuits, FIG. 1 shows a schematic block diagram of a signal generator 8. A CPU (central processing unit) 10 controls the operation of the various components of the signal generator 8 via a system bus 22. A memory 12 that includes ROM and RAM memory, a hard disk drive and the like stores executable programs for controlling the functions of the signal generator 8 as well as output waveform data. The signal generator displays basic waveform data (waveforms of sine, pulse, etc.) on a display 14 and has a user interface (operation keys, etc.) 16 for changing parameters (frequency, voltage, etc.) of the waveform data. A user edits the waveform data, which may represent waveforms for separate output signal channels using the interface 16. The edited waveform data is stored in memory 12. The edited waveform data in the memory 12, which may contain more than one waveform data file, is transferred to digital to analog converters (DACs) 18 and 20. The DACs 18 and 20 convert the waveform data files into analog output signals. The DACs are provided according to the number of desired channels. A signal generator as described above is disclosed in U.S. Pat. No. 5,371,315, for example.
One method of changing the parameters of the output waveform data is for a user to directly inputs numerical parameter values through the interface 16. Another method is displaying the waveform or waveforms on the display screen 14 and allowing the user to modify the shape of the waveform or waveforms. If the signal generator has two output channels and it is necessary to consider the phase relationship between the waveforms output to each channel, it is easier to edit the waveforms parameters through the displayed waveforms than editing only the numerical values. Even if the waveform or waveforms can be set by the numerical values, it would be helpful for the user to display the waveforms because it enables the user to confirm them visually. It is, therefore, preferable to display the waveforms on the screen for editing parameters as well as the characters and numbers of the channels.
Operability of the signal generator would be improved if the signal generator displays characters, numbers, waveforms and channels for editing waveform parameters by rearranging the waveform parameter data and channels combinations according to the output signals. Therefore what is desired is to provide user interface that allows a user to change parameter edit screen layers easily and instinctively to a desired combination of characters, numbers, waveforms and channels and also provide easy learning of the operation of a signal generator.